1. Field of the Invention
The invention relates to the field of packaging and in particular to packaging for electronic circuits and electronic media which packaging provides some type electrostatic shielding.
2. Description of the Prior Art
The electronic industry manufactures and uses as part of their finished products a variety of individual component devices which are highly sensitive to static electricity. Static electricity is generally created by the human body, or human clothing, or insulating materials such as plastics. Static electric charges emanate outward and can effect a sensitive electronic device if the device is penetrated by the charge or comes within the charge's field. The effect to the device can be destruction, or degradation of its ability to function over its lifetime. The failure of sensitive devices result in the loss of millions of worth of products in the electronics industry and the loss of reliability and credibility of products. Protection of static sensitive devices is of prime importance to the electronics industry. Protection of static sensitive components is accomplished by allowing them only to be exposed in static-safe work areas, or enclosing them in static-free and static shielding protective packaging. Protective packaging is a critically important means of containment and transport for sensitive components. The electronic industry purchases many millions of dollars worth of static protective packaging each year.
Electrostatically shielded rooms and enclosures, generally known as Faraday cages, are well known and are utilized in all types of configurations and sizes to protect electronic devices or media such as magnetic tape, cards and the like from damage or alteration by stray electrostatic fields. Such enclosures or containments range from structures in which large devices can be positioned, such as aircraft or trucks down to the size of the electronic device itself. Such Faraday cages generally are comprised of a conductive skin which completely encloses a space. Such skin is often fabricated from a conductive screening such as a woven copper or metallic mesh.
Circuit boards carrying digital integrated chips very often contain firmware which is also susceptible to damage by stray electrostatic fields. Such integrated circuits are packaged for the purposes of shipping in flexible package bags which have a metalized surface. The prior art has used for antistatic packaging of electronic devices or media chemically treated polyethylene bags, polyethylene bags treated with conductive carbon, carbon ink on polyethylene bags, metalized laminated film bags, paper and metal foil laminated bags, paper and heavy carbon coated bags, and carbon saturated paper bags. Such plastic or treated packaging while effective to protect the circuit from electrostatic damage are not biodegradable and recyclable.
After use, the packaging in which the circuit or electronic media is transported is typically thrown away. The prior art plastic metal or treated packaging is virtually indestructible by all ordinary environmental agents and will for practical purposes last forever. At the present time, millions if not billions of such packages are used annually by electronic manufacturers throughout the world. Therefore, there has arisen a serious environmental concern that such electronic packaging will accumulate as a permanent nondegradable waste product in the landfills throughout the world.
Therefore, what is needed is a practical, inexpensive packaging which provides adequate electrostatic shielding for electronic products and media, but which when its propose has been served can be disposed of as a biodegradable product or recycled.